Antishock spin device

ABSTRACT

1. An improved ordnance fuze-arming mechanism for use on a spinning missile, said mechanism comprising in combination: a cylindrical fuze body having a flat circular face located in a plane perpendicular to the axis of missile rotation, first and second flat planar leaf members, each of said members having one of its ends pivotally connected to said face at spaced-apart points such that a flat side of each leaf member is movable around its pivot point parallel to said face, the other end of each leaf member extending adjacent the perimeter of said face and curving to engage each other at their outermost ends, the other end of the first leaf member having an elongated serrated blade portion, said blade portion having opposite edges with a series of adjacent grooves formed in each edge, the grooves on opposite edges being arranged so that the inner apexes of the grooves in one edge are opposite the outer apexes of the grooves in the other edge, the other end of said second leaf having an elongated opening therein for receiving said serrated blade portion, spring means connected to said fuze body and to the pivoted ends of said members so that said blade portion is urged into said opening, said opening having opposite inwardly projecting lips forming an entrance and adapted to engage said blade such that when one lip engages an inner apex on one edge, the other lip is opposite but just out of contact with an outer apex on the other edge, said lips thereby alternately locking and unlocking with said grooves when said leaf members are urged apart by continuous centrifugal forces produced by continued missile rotation, the alternate locking and unlocking of said leaf members continuing until said members separate, and means in said fuze to effect detonation when said leaf members separate.

United States Patent [72] Inventor John F. Burke Silver Spring, Md. [21] Appl. No. 715,162 [22] Filed Feb. 13, 1958 Oct. 19, 197 l The United States of America as represented by the Secretary of the Army [45] Patented [73] Assignee [54] ANTISHOCK SPIN DEVICE Primary ExaminerBenjamin A. Borchelt Assistant Examiner-Thomas H. Webb Att0rneysW. E. Thibodeau, T. J. Lynch, F. E. McGee and .I.

D. Edgerton CLAIM: 1. An improved ordnance fuze-arming mechanism for use on a spinning missile, said mechanism comprising in combination: a cylindrical fuze body having a flat circular face located in a plane perpendicular to the axis of missile rotation, first and second flat planar leaf members, each of said members having one of its ends pivotally connected to said face at spaced-apart points such that a flat side of each leaf member is movable around its pivot point parallel to said face, the other end of each leaf member extending adjacent the perimeter of said face and curving to engage each other at their outermost ends, the other end of the first leaf member having an elongated serrated blade portion, said blade portion having opposite edges with a series of adjacent grooves formed in each edge, the grooves on opposite edges being arranged so that the inner apexes of the grooves in one edge are opposite the outer apexes of the grooves in the other edge, the other end of said second leaf having an elongated opening therein for receiving said serrated blade portion, spring means connected to said fuze body and to the pivoted ends of said members so that said blade portion is urged into said opening, said opening having opposite inwardly projecting lips forming an entrance and adapted to engage said blade such that when one lip engages an inner apex on one edge, the other lip is opposite but just out of contact with an outer apex on the other edge, said lips thereby alternately locking and unlocking with said grooves when said leaf members are urged apart by continuous centrifugal forces produced by continued missile rotation, the alternate locking and unlocking of said leaf members continuing until said members separate, and means in said fuze to effect detonation when said leaf members separate.

' PATENTEUUBI 19 ISYI SHEET 10F 2 PATENTEDum 1 9 |97l SHEET 2 [IF 2 R mm R WU 8 F M J M BY uf l ANTISI-IOCK SPIN DEVICE The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to arming systems in general, and in particular to an improved two-leaf anning system for use in fuzes which are used on spinning missiles developing low centrifugal forces. Missiles such as mortars, rockets and bombs have either small diameters or spin at relatively low velocities so that large centrifugalforces cannot be developed.

Using the centrifugal force produced by spin to effect arming is desirable because of the improbability of such forces being developed by mere handling of the missile. However, the use of centrifugal force alone to effect arming is not always a safe expedient because impact shock and acceleration forces produced by dropping the missile may simulate centrifugal force and result in arming.

To overcome this accidental arming problem,-systems have been designed and are known in the art which require some minimum sustained force acting for some minimum period of time before arming can occur. One way of accomplishing this is to provide a series of mutually dependent leaves which respond to centrifugal forces and move sequentially in response to the sustained force to arm the fuze. The primary drawback with such systems is that they are relativelycomplex and therefore inherently unreliable. Recognizing the disadvantages in complex arming systems, those skilled in the art have attempted to develop a two-leaf spin release system. However, the prior art has not been able to provide a satisfactory two-leaf system which solves the impact problem. This is chiefly because the necessary minimum time requirement over which a force must be provided to produce arming could not be built into the two-leaf system. This is especially true where low-order centrifugal forces are involved because the arming system must be more sensitive and therefore more susceptible to impact.

The present invention overcomes the disadvantages attendant in prior art two-leafspin release systems, by providing interlocking leaf end portions which are designed to quickly dissipate energy produced by impact and which respond only to continuous centrifugal forces produced when the missile is launched or fired.

It is an object of this invention, therefore, to provide an interlocking two-leaf spin release system which. will be relatively immune from premature arming caused by dropping, and yet will be responsive to centrifugal forces of low or high order acting for some minimum period of time.

It is another object of this invention to employ the novel interlocking leaf system in a fuze device.

The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, in which:

FIG. 1 is a plan view of a fuze in accordance with the invention showing the anning leaves in an unarmed or safe position.

FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1.

FIG. 3 is an enlarged sectional view showing the stab primer and firing pin arrangement in an unarmed position taken along the line 3-3 of FIG. 2.

FIGS. 4 to 8 are enlarged plan views showing the sequence of movements of the two leaf members in response to continuous centrifugal forces.

Referring first to FIGS. 1, 2 and 3, there is shown a discshaped cylindrical fuze body 10, which can be mounted in a spinning missile such as a mortar. Fuze body 10 is provided with a cover 104 and a flat face 12 which is substantially perpendicular to the axis of rotation of the fuze body and the missile. Leaf members 11, 11a are pivotally mounted to face 12 at pivot ends l3, 14 by means of screw shafts l5, l6 and are urged towards each other by springs I7, 18 which bear against raised edges 17a, 18a on fuze body 10. One end of each screw shaft is connected to one end of each spring and the other ends of the screw shafts are fixed-to leaf members 11,111: so that the shafts can be turned at their springends in order to vary the tension which the springsexe'rt on the leaf members. Leaf member 11 has a flat portion -19, which can be engaged by hook end 20a of hook 20. Hook "20 is pivotally connected I to face 12 by pin 21 and is designed to'conta'ct attached to one end of half shaft 23.

I-Ialf-shaft 23 is rotatably mounted to bore 24 which extends perpendicularly to face 12 and intersects bore 26. When hook end 20a engages flat portion 19, hook 20.fixes;the positidr'i'of pin 22. .lnthis position of pin 22,'half-shaft 23 is turned so'that flat portion 39 protrudes into bore-'26 and acts as a' sto'pfor carrier 25.

Bore '26 has screw base 29 at one end carrying firing pin 31 and providing a substantially gastight closure for bore 2652 the other .end of bore 26 is compression spring 30 which enpin 22 which is gages the end of carrier 25 carrying stab primer 27. Carrier 25 has an opening 28 through which the' firing -pin.3l 'cari" pass and strike primer 27. Spring 30 urges carrier 25 towardsba'se 29 and against flat portion 39 when the latter is held soas to protrude into bore 26.

Located centrally of fuze face, 12 ischamber 40 having opening 32 which communicates with bore '26.'Slidable within chamber 40 (FIG. 2) is piston 41 forming a substantially gastight seal for chamber 40 and adapted'to'be drivenby'gas pressure towards cover 10a. Attached, to piston 4| is'membe'r 410 which is adapted to penetrate an opening in cover 10a and carries striker 42. Striker 42 is capable of contacting a percussion primer, or other means, generally indicated by numeral 43, which causes the missile to arm.'Persons skilled in the-art will recognize other possible uses for utilizing the movement of striker 42.

Spring 30'urges carrier 25 into contact with flat portion, of half-shaft 23 protruding into bore 26.'-When flat portion 39 is at an angle to the lower edge of bore'26 it contacts carrier 25 and prevents movement thereof towards'base 29, but when flat portion 39 is turned to align with the lower edge of-the bore 26 it permits the carrier to slide over it.

When, as-a result of centrifugal forces due to rotation, leaf members 11, 11a separate to the point that hook end 20acan no longer be held by flat portion 19 of leaf, hook 20 will'be free to swing about pivot 21 releasing'for'rotative movement pin 22 and half-shaft 23. Carrier 25 can then press flatportion 39 into alignment with the lower edge of bore 26 andcar'ry primer 27 into contact with firing pin 3]. Gases producedby detonation of primer 27 expand into bore 26, then through opening 32 and into chamber 40 driving piston 41 towards cover 10a. Striker 42 is thereby driven through an opening in cover 1011 and into contact with an ampule or percussion primer 43.

FIGS. 4 to 8 show in detail the construction and'movement of the novel leaf members 11, lla which are responsive only to continuous centrifugal forcessLeaf members 11, have interlocking end portions generally designated by numbers 11 l 1110. Line C-c' (FIG. 6) indicates the approximate longitudinal axis of elongated serrated blade portion 11]. End portion llla has an elongated opening 45 therein and lips 11 and i define the entrance to this opening. Serrated blade portion 111 is composed of a series of angular grooves a, b, c, d, e, which terminate in outer apexes Y, Y, Y on the upperedge and outer apexes X, X, X" on the lower edge. Inner upper and lower apexesare referred to in FIG. 7 as W, W, and Z, Z, Z, respectively. The angle formed by the grooves is approximately The distance between lips h and i measured vertically with respect to the longitudinal axis C-C of portion 111 is less than the vertical distance between opposite adjacent outer apexes Y, Y, Y" and X, X, X", but greater than the distance between vertically opposed edges of grooves a, b, c, d, e. Each outer apex is shown as substantially vertically aligned with an opposite inner apex. However, this last relationship is not absolutely critical and small variations in the distances between opposed apexes from the vertical will not prevent the leaf members from operating.

FIG. 1 shows the leaf portions in the unarmed position where lips h and i engage leaf shoulders a and b. Leaf shoulders a and b connect the grooves a and b with edges of the body of leaf 11, and the point of intersection between the shoulders a and b and the grooves a and b can be determined by drawing straight lines through apexes Y, Y, Y" and X, X, X". The points of intersection of these lines with leaf 1 l determine the points of connection between grooves a and b and shoulders a and b. Lips h and i are retained in this position by the action ofspn'ngs l7 and 18.

FIG. 4 shows the first position that the leaf members may assume when subject to either centrifugal force or shock and acceleration forces acting on the perimeter of the fuze body 10. In this position groove a is forced into contact with lip h because leaf 11 tends to pivot about end 13. Leaf 11a also tended to pivot but was restrained by lip i engaging groove b. If the separating force is sustained, leaf 1 la can then move to the position shown in FIG. 5. Leaf ll initially pivots so that groove is forced into engagement with lip h as shown in FIG. 4. Lip i will have cleared outer apex X when lip h is in engagement with the bottom of groove a that is, in inner apex W. Leaf II will not pivot because lip h is abutting groove a on leaf II. Lip i on leaf 11 having cleared outer apex X permits rotation of leaf Ila. Leaf 11a is thereby unlocked for pivotal movement and pivots in response to continued centrifugal force until lip ienters inner apex Z and abuts groove d (FIG. 5), at which time lip h clears outer apex Y. Leaf 11 under continuous centrifugal force is unlocked to pivot until lip h enters inner apex W and abuts groove c, at which time lip i clears outer apex X. The described alternate locking-unlocking of leaf member 11 and Ila continues until the serrated blade 1 ll pivots out of opening 45 (FIG. 8). No translation between lips h and i and serrated blade lll occurs because the lips h and i and the grooves in blade 111 are designed so that one of the lips always assumes a position to clear an outer apex in one edge when the other lip is in abutting engagement with a groove in an opposite edge.

The leaf separation action produced by the combinations of shock and acceleration forces produced by impact is most pronounced when the fuze impacts in the direction of arrow P (FIG. 4). Under such conditions groove a of leaf 11 will be thrown into locking engagement with the lip h of leaf 11a and thereby substantially dissipate the initial energy of the impact. Should the impact force be of high magnitude it may last over a longer period, in which case the leaf portions 111, 111a might assume the position shown in FIG. 5. However, the alternate unlocking of the leaf members would quickly dissipate any remaining energy and the springs 17 and 18 finally restore the leaf members to the position shown in FIG. 1. Of course, the responsiveness of the leaf members to separating forces depends primarily upon the pressure which the springs 17 and I8 exert on the leaf members 11, Ila. As pointed out above, the pressure these springs exert on the leaf members can be regulated by turning the screw shafts 15, 16.

Complete dissipation of the energy of impact will be effected by the locking-unlocking action described above without the leaf members spreading far enough apart to release hook end 29a.

It will be evident that only when the separating force is acting upon the leaf members for some continuous predetermined period of time will the alternate locking-unlocking movement proceed long enough for the leaf members to separate and release the hook end 20a from the flat portion 19 of leaf 11 and thereby effect arming of the fuze. The period of time can be easily varied by varying the number of apexes on portion 11].

FIGS. 6 to 8 inclusive, show the progressive alternate locking-unlocking movements which occur between the leaf members when the fuze body 10 is subjected to low-order, continuous centrifugal forces. The angles shown in the FIGS. are approximate and depend to a large extent upon the particular dimensions of the grooves a, b, c, d, e.

The above description discloses an arming device employing but two leaf members which respond only to continuous centrifugal forces acting over some predetermined period of time and which device is safe against shock from any direction. Centrifugal forces of high magnitude are not required to operate the novel interlocking leaves and the system can therefore by used on missiles which develop low orders of centrifugal forces.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claims.

I claim as my invention:

1. An improved ordnance fuze arming-mechanism for use on a spinning missile, said mechanism comprising in combination: a cylindrical fuse body having a flat circular face located in a plane perpendicular to the axis of missile rotation, first and second flat planar leaf members, each of said members having one of its ends pivotally connected to said face at spaced-apart points such that a flat side of each leaf member is movable around its pivot point parallel to said face, the other end of each leaf member extending adjacent the perimeter of said face and curving to engage each other at their outermost ends, the other end of the first leaf member having an clongated serrated blade portion, said blade portion having opposite edges with a series of adjacent grooves formed in each edge, the grooves on opposite edges being arranged so that the inner apexes of the grooves in one edge are opposite the outer apexes of the grooves in the other edge, the other end of said second leaf having an elongated opening therein for receiving said serrated blade portion, spring means connected to said fuze body and to the pivoted ends of said members so that said blade portion is urged into said opening, said opening having opposite inwardly projecting lips forming an entrance and adapted to engage said blade such that when one lip engages an inner apex on one edge, the other lip is opposite but just out of contact with an outer apex on the other edge, said lips thereby alternately locking and unlocking with said grooves when said leaf members are urged apart by continuous centrifugal forces produced by continued missile rotation, the alternate locking and unlocking of said leaf members continuing until said members separate, and means in said fuze to effect detonation when said leaf members separate. 

1. An improved ordnance fuze arming-mechanism for use on a spinning missile, said mechanism comprising in combination: a cylindrical fuse body having a flat circular face located in a plane perpendicular to the axis of missile rotation, first and second flat planar leaf members, each of said members having one of its ends pivotally connected to said face at spaced-apart points such that a flat side of each leaf member is movable around its pivot point parallel to said face, the other end of each leaf member extending adjacent the perimeter of said face and curving to engage each other at their outermost ends, the other end of the first leaf member having an elongated serrated blade portion, said blade portion having opposite edges with a series of adjacent grooves formed in each edge, the grooves on opposite edges being arranged so that the inner apexes of the grooves in one edge are opposite the outer apexes of the grooves in the other edge, the other end of said second leaf having an elongated opening therein for receiving said serrated blade portion, spring means connected to said fuze body and to the pivoted ends of said members so that said blade portion is urged into said opening, said opening having opposite inwardly projecting lips forming an entrance and adapted to engage said blade such that when one lip engages an inner apex on one edge, the other lip is opposite but just out of contact with an outer apex on the other edge, said lips thereby alternately locking and unlocking with said grooves when said leaf members are urged apart by continuous centrifugal forces produced by continued missile rotation, the alternate locking and unlocking of said leaf members continuing until said members separate, and means in said fuze to effect detonation when said leaf members separate. 